Method employing barrier means to submerge particles in a molten metal stream

ABSTRACT

A continuous melting, smelting or processing method including the steps of: Providing a substantially continuous moving molten metal bath, preferably in a coherent mass such as a stream, and introducing into the bath a substantially continuous charge of metal, metal ores, compounds or concentrates thereof, the metal of either of which is substantially the same as that of the moving molten metal bath, and utilizing physical force to urge the metal, metal ores, compounds or concentrates thereof into and beneath the surface of the bath, and to so hold the charge therebeneath such surface so as to accelerate their chemical reaction or dissolution, thereby increasing the volume of molten metal produced per unit of time.

United States Patent Proler Dec. 30, 1975 [54] METHOD EMPLOYING BARRIER MEANS 3,157,490 11/1964 Wiberg 75/40 o SUBMERGE PARTICLES [N A MOLTEN 3,202,408 8/1965 Huhtala et a1. 75/65 R X ,32 ,671 6/1967 Worner..... 75/60 X METAL STREAM 3,536,478 10/1970 Ankersen 75/65 R [76] Inventor: Sam Proler, 5106 Contour Place, 3,614,079 l0/l971 Ha at 75/65 R X Houston, Tex 77035 3,770,420 ll/l973 Spear et al. 75/65 R X [22] Filed: 1973 Primary ExaminerAllen B. Curtis [21] Appl. No.: 391,878 Assistant ExaminerThomas A. Waltz Related US. Application Data Continuation-in-part of Ser. Nos. 306,429, Nov. 4, 1972, Pat. No. 3,881,915, and Ser. No. 161,905, July 12, 1971, abandoned, which is a continuation-in-part of Ser. No. 29,325, March 30, 1970, abandoned.

Attorney, Agent, or Firm-Bernard A. Reiter [57] ABSTRACT A continuous melting, smelting or processing method including the steps of: Providing a substantially continuous moving molten metal bath, preferably in a coherent mass such as a stream, and introducing into the bath a substantially continuous charge of metal, metal ores, compounds or concentrates thereof, the metal of either of which is substantially the same as that of the moving molten metal bath, and utilizing physical force to urge the metal, metal ores, compounds or-concentrates thereof into and beneath the surface of the bath, and to so hold the charge therebeneath such surface so as to accelerate their chemical reaction or dissolution, thereby increasing the volume of molten metal produced per unit of time.

19 Claims, 13 Drawing Figures US. Patent Dec. 30, 1975 Sheet 1 of5 3,929,465

US. Patent Dec. 30, 1975 Sheet 2 of5 3,929,465

FIG. 6

US. Patent Dec.30,1975 Sheet3of5 3,929,465

mll'

U.S. Patent Dec. 30, 1975 Sheet 4 of5 3,929,465

U.S. Patent Dec. 30, 1975 Sheet 5 of5 3,929,465

METHOD EMPLOYING BARRIER MEANS TO SUBMERGE PARTICLES IN A MOLTEN METAL STREAM This Application constitutes a continuation-in-part of my earlier Application entitled A METHOD FOR ENHANCING REDUCTION OF ORES, OXIDES AND MELTING OF METALS BY MAGNETIC FORCES filed Nov. 4 1972, and bearing Ser. No. 306,429 now U.S. Pat. No. 3,881,915 and of my application entitled ANOTHER METHOD FOR PRO- CESSING METALLIC ORES AND/OR METALLIC COMPOUNDS, filed July 12, 1971, and bearing Ser. No. 161, 905, now abandoned, but which is a continuation-in-part of my earlier application Ser. No.29,325, entitled METHOD FOR PROCESSING METALLIC ORES AND/OR METALLIC COMPOUNDS, filed Mar. 30, 1970, now abandoned.

BACKGROUND OF THE INVENTION In my earlier aforementioned application Ser. No. 161,905, explanation is set forth describing certain features and advantages in a method for continuously processing metallic ores or compounds thereof by utilizing a moving stream of molten metal. The method, when directed to the objective of reduction of metal oxides, suggested that the ore or oxide be charged into and beneath the surface of the molten stream, and that such charged material be of a metal that was substantially the same as that of the stream itself. The stream mass was thus, in effect, the environment in which the ores or oxides were reduced. The reduction was therefore carried out in the most efficient manner because of the intimate contact between the charged material and the stream mass. Optimal heat transfer between the stream and charge was thus accomplished with substantially no heat loss. It was there visualized that a circulating stream moving in a closed loop trough could, in itself, constitute the vehicle for continuously processing ores or oxides, or metal particles, into additional molten metal. While the charge material was fed to the stream, tapping of the product metal could take place at one point while slag removal could occur at another. The more obvious advantage of such a method thus resides in the superior heat transmission efficiency from the source (the stream) to the charge particle (ore, oxide or metal particle), by reason of the submersion of the latter within the former.

My subsequent aforementioned application Ser. No. 306,429, now U.S. Pat. No. 3,881,915, describes the problem inherent in processing particle size ores, oxides and metals. Industrial utilization of such particle sizes could not be accomplished because of their tendency to float upon the surface of a molten bath. As a consequence such particles were slow to wet and dissolve, particularly if the molten bath was of static nature. Due to the slow wetting action, such particles could not be fed at a significant rate to a bath without causing a freeze-up" at the point of introduction. Industrial utilization of such particle size ores, oxides and metals was, therefore, substantially non-existent and, common industrial by-products such as steel industry mill scale, scarfer grit and flue dust were not efficiently utilized. The application Ser. No. 306,429 was directed to a solution for the aforedescribed problem. This was accomplished through the utilization of magnetic forces which would act upon metal particles to force them into and beneath the molten stream. The Application further envisioned such concept within the earlier described moving molten metal stream, which may travel in a closed loop path, and into which the ores, oxides or metal particles were to be introduced. The magnetic field would thereby cause submersion of the charge into the stream mass, thus facilitating heat transmission from the stream to the particles because of the immersion of the particle surface within the stream.

The present application discloses, in addition to my application Ser. No. 306,429, now U.S. Pat. No. 3,881,915 a further method for effectively utilizing particle size ores, oxides and metals. It differs, for example, from said earlier filed application in that attention is here directed to the processing of metal which may not be possessed of magnetic characteristic. This method is therefore principally directed to the processing of non-ferrous metal charges, metal ores, compounds of their concentrates. Since this method encompasses the use of the moving molten metal stream, also disclosed in my application Ser. No. 161,905, now abandned, it will be recognized that the concept herein may be utilized to accomplish any of a plurality of metal processing objectives, such as for example, reduction, melting, refining, smelting, alloying and others. In accordance herewith, however, the method is directed to the processing of metals not having magnetic characteristics. Therefore there is disclosed a method by which magnetic and also non-magnetic particles, their ores and their concentrates may be expeditiously forced into and beneath the surface of a moving molten metal stream so as to markedly enhance the processed tonnage per unit of operating time.

BRIEF SUMMARY OF THE INVENTION The present invention pertains to a method for substantially continuously conducting any of a plurality of the processing steps to which metal pieces and particles, or their ores and compounds and concentrates thereof may be subjected. More particularly, the invention pertains to a method for substantially continuously accomplishing any of a plurality of metal processes by utilizing a moving molten metal stream as the processing environment, and by charging tothe stream metal particles, or the ores or compounds or concentrates thereof. For exemplary purposes, it is anticipated that the present method may be directed to the processes of reduction, refining, smelting, alloying or even melting.

The industrial utilization of particle size metals, ores or concentrates thereof has, theretofore, been substantially frustrated by the inability to introduce such particles into a molten metal bath in a manner providing for their expeditious dissolution. It is commonly known that the rate of introduction of metal particles to a bath is determined by the rate at which the particles wet and subsequently dissolve. To introduce too slowly to a bath is economically not feasible because of the continuous loss of heat from the bath itself and the consequent high production costs due to the relatively small amount of end product. Introduction of the metal particles at too fast a rate would result in a lowering of the temperature of the bath at the point of introduction and the concomitant probability of a freeze-up at such charging area. As a result, conventional processing of metal particles for such purposes as reduction melting, smelting and others, has been substantially non-existent. This is especially unfortunate because of the processing advantages inherent in a molten bath environment, particularly a molten bath environment moving as a coherent mass, such as a stream. One of the most pronounced of these advantages is the superior heat transmission which takes place from the molten stream to the charged particle. Because the charged particle is substantially immersed beneath the surface of the stream, there is no heat loss from the particle itself as is commonly experienced by particles that tend to float upon or reside upon the surface because of their lighter weight.

In accordance herewith, physical objects are employed in order to force the charged material, generally metal particles, ores, compounds or the cencentrates thereof, into and beneath the surface of the stream. In so doing the slow wetting action and consequent uneconomical processing generally prevalent with small sized charge material is largely avoided. For example it will be apparent that introduction of metal particles into a mass of moving molten metal may be accelerated without concern of a freeze-up at the area of introduction of the charge.

Another principal advantage of the invention resides in a method whereby relatively small sizes, such as particles of metals and the ores, oxides or concentrates thereof, may be processed in an economically efficient and continuous manner.

Another advantage of the invention resides in a method for maximizing the use of available heat in a molten stream by causing accelerated wetting of metal particles charged thereto, this through the utilization of physical forces acting upon the metal particles at or near the stream surface.

A still further feature annd advantage of the invention resides in a method for continuously reducing, refining, smelting, alloying, melting or otherwise processing metal particles or the ores, compounds or concentrates thereof.

Still another feature and advantage of the invention resides in a method for processing metal particles, the ores, compounds and concentrates thereof, such as in the reduction of a continuous charge of iron oxide to molten iron, on a continuous basis.

Still another feature and advantage of the invention resides in a method for efficiently processing metals of particle size, such as the ores and compounds and concentrates thereof on a continuous and economically efficient basis through the use of a molten stream and physical forces acting on the particles.

These and numerous other features and advantages of the invention will be more clearly recognized and appreciated upon a reading of the following detailed description, claims and drawings wherein like numerals denote like parts in the several views and wherein:

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a molten metal stream and upon which a suggested form of physical barrier means is applied in accordance with the invention.

FIG. 2 is an end view of FIG. 1.

FIG. 3 is a side view of a molten metal stream upon which another form of physical barrier means is utilized in accordance with the invention.

FIG. 4 is a side view of a molten metal stream on which yet another form of physical force or barrier means is applied in accordance with the principles of the invention.

FIG. 5 is a side view ofa molten metal stream and on which still yet another form of physical force or barrier means is applied in accordance with the principles of the invention.

FIG. 6 is a side view of a molten metal stream and upon which yet still another form of physical force is applied in accordance with the principles of the invention.

FIG. 7 is a top view, in partial cutaway, of a furnace apparatus having communicating therewith a molten metal stream in accordance with the principles of the invention.

FIG. 8 is a front view of FIG. 7 showing the apparatus in partial cutaway and in conjunction with other physical force means.

FIG. 9 is a top view of another form of furnace apparatus having a molten metal stream in communication with each end thereof.

FIG. 10 is a section through the furnace apparatus and stream of FIG. 9 along the plane 10l0 thereof and showing a physical force means.

FIG. 11 is yet another form of furnace apparatus in which subsurface charge introduction is used in conjunction with the stream concept of the invention for melting purposes.

FIG. 12 is a top view of FIG. 11 along the plane 99 thereof.

FIG. 13 is a side view of yet another form of the invention which subsurface introduction is used for reducing purposes.

DETAILED DESCRIPTION OF THE INVENTION The term concentrate shall herein refer to metallic ores or oxides thereof which may have been purified by the removal of gangue and other impurities; an example is the extraction of copper from low grade copper sulfide ores including generally the steps of crushing, grinding, classification, flotation, and filtration. Further, concentrate shall generally make reference to metal of non-magnetic character although in certain applications it will be recognized that the concentrate of the metal may be characterized by magnetic characteristic. Still further, the term concentrate as used herein, may include the compound form of metals, unless the compound form is specifically designated, when such compound form of metal may be processed in accordance with the methods disclosed herein. Compounds, as used herein, includes ores or concentrates thereof, such as for example iron oxide.

The term metal particles or particles shall generally refer but not to limited to metal pieces, fragments or other waste generated from metal operations of all types and which may be used as charge material for the method disclosed herein and may, for example, constitute borings, punchings and shredded pieces or shavings of metals.

The term charge or charged material or charge of metal herein refers to the material to be processed in the molten metal stream and will generally include metallic ores, compounds, or concentrate thereof, and metal particles.

Oxides shall refer, when appropriate, either to man made oxides such as, for example, mill scale or briquets, pellets, sintered material and other beneficiated or agglomerated ores; and natural oxides or metals as they occur in their natural elemental state.

The term process or processing herein refers to any of the plurality of melting or metallurgical steps which metal ores, metal compounds and concentrates and metal particles may be subjected to and are in tended to include but not be limited to such steps as reducing, smelting, refining, alloying and melting.-

One of the most efficient and economical methods for accomplishing rapid wetting and dissolution of metal ores and the compounds and concentrates thereof is to introduce them over an extended area of a molten metal stream which is continually moving past the area of introduction. Depending upon the rate of lineal movement of the stream and other such factors as its surface area, depth and the like, the amount of material which is charged to the stream per unit of time may vary. Generally, the greater the rate of linear movement of stream surface, the more volume of charge material may be introduced per unit of time. If too great a quantity of charge material is introduced to the stream before the previously charged material has been moved away by the stream current, a freeze-up at the point of introduction may possibly occur because of the insufficient availability of heat to be transmitted from the stream mass to the mass of charge introduced. For this reason more optimal heat transmission from the stream mass to the charged material can be accomplished if the stream is characterized by some internal turbulence rather than laminar flow. This is particularly true when the charge material is a solid in particle size, the density of which is relatively light by comparison to the density of the stream and as a consequence of which the particle tends to flaot on the surface of the stream and be generally thrown about. Utilization of a stream of molten metal as the vehicle for processing relatively large amounts of charge material per unit of time constitutes a superior, if not optimal method when compared to batch or other types of static molten masses as the processing media for continuously charged material.

Although a moving molten metal stream may thus obviate a freeze-up of the charge at the point of introduction, the problem of immersing the charge beneath the stream has not, heretofore, been satisfactorily accomplished. In processes requiring effective transmission of heat from the stream to the charged particles having a lesser density than the stream itself, an effective method is realized in accordance with the principles disclosed hereinafter. Such principles embody the utilization of a physical force or barrier means acting upon the surface of the stream in order to induce immersion of the charge therebeneath. With reference to FIG. 1 there is shown a suggested apparatus for accomplishing this objective. Here, there is provided a moving molten metal bath 3, preferably in the form of a stream. The stream may be induced in a number of ways such as by an induction conveyor or mere gravity. The moving molten metal bath or stream 3 differs from a molten bath of static character in that the area of molten metal into which a charge is introduced is maintained at a substantially constant temperature substantially independently of the amount or rate of material charged. Provision for movement of the molten metal bath as a stream, as opposed to mere stirring, insures that the molten metal in the vicinity of the charging area will be moved away therefrom. Significant advantage is achieved in the rate of charge processing through the use of the moving molten metal stream because of elimination of the possibility of solidification, or decreased viscosity, in the stream at' the area of introduction, which normally would occur with too great a charging rate. Use of a molten bath, moving uniformly in a substantially coherent direction so as to produce a stream of molten metal which acts as the processing vehicle, or the processing environment, substantially eliminates rate of charge limitations and provides for utilization of a continuous processing ability.

Disposed in adjacent relation to the stream is a hopper or other appropriate charging means 5 and from which charged material 17 is introduced to the stream. The charged material may consist of a metallic ore or the compound or concentrate thereof; which is to be processed such as by reduction or smelting for example. In a reduction process, the reducing agent used for example to remove oxygen or sulfur, may be introduced like the charge, or it may pre-exist in the stream, or in the environment above. Other appropriate agents, such as fluxes, may be added to the stream, as may heat whenever same is necessary. The charge may also be metal particles as defined herein, which may be processed, such as by melting. Although the drawings herein may generally describe the introduction of charge material to the surface of the stream it will be recognized that the principles disclosed herein may be practiced independently of the method of charging. Therefore the charge may be introduced from beneath the stream surface, or otherwise, and the method may be practiced upon such charge material if it has a tendency to float at the surface.

Further, with reference to FIGS. 1 and 2 there is shown physical barrier means 7, these being in the forms of drums which may be rotatably mounted 9 so as to have their circumferential surface 7a in contact with the surface of the stream 3, or submerged slightly therebeneath. The drums function to provide a physical force which acts upon the stream surface in order to effect submergence of the charge 17 should the latter be floating at or near the stream surface. The charge 17 will normally float at or near the surface of the stream when its density is lighter than that of the molten metal in the stream. Because the charge is not completely immersed within the stream, and to the heat thereof, the charge is slow to wet and hence dissolve. Due to the presence of drums 7, or other type of physical force, the charge is forced into and beneath the surface of the stream so as to achieve total immersion and hence maximum heat transmission from the molten metal to the charge itself. In this manner the possibility of heat loss from the charge is substantially eliminated while the absorption of the heat to the charge is maximized.

The stream 3 is adapted to flow within the confines of a trough 11 or other defined path. The trough 11, as disclosed in my earlier aforementioned Application, may be designed to convey the molten stream beneath two predetermined points such as between two furnaces (not shown) or the trough may be designed to carry the stream in a continuous or endless path, such as would be the case if the trough traversed a circle or other closed loop design. In the latter event, the charge 17 may be continuously introduced to the stream 3 at a rate depending upon a number. of factors such as the rate of stream current, its volume, width, depth, and the absorption rate of the particular material of the charge within the composition of the stream. it may be visualized that forced submersion of the charge within the stream and beneath the drums 7 will effectuate maximum exposure of the charge to the stream heat so as to promote wetting and hence improve the cohesion of the charge within the mass of the stream, this con- 7 comitantly reducing the buoyancy of the charge so that after the stream current carrying the charge has passed the drums, the likelihood of the charge resurfacing is remote. Due to the differing chemical compositions and physical characteristics of varying charges it may therefore be advisable, in order to accomplish the objectives hereof, to mount the drums in series such as shown in FIG. 1. Although a single drum may be sufficient to accomplish the stated end it will similarly be recognized that any number of drums, or physical barrier means, mounted in series, may be decreed depending upon the circumstances.

The drums 7 may be either statically, or dynamically mounted as referred to hereinabove. In the latter case the drums may be driven by the inherent force in the current of the stream or they may be driven by motive means 13 in either a clockwise or a counter-clockwise direction depending upon the relative effectiveness which may be achieved. Effectiveness in accomplishing submergence of the charge may be influenced by nu merous factors such as the size of the charge particles or pieces, their relative buoyancy and other such factors as may be readily observed during start-up procedures. If the drums are to be rotated in the direction of the stream itself it has been found that effective wetting action of the charge is accomplished if the drums are rotated at a circumferential rate of linear movement which is different from the linear rate of movement from the stream itself. This, as pointed out in my earlier application Ser. No. 161,905 achieves an effective rate of introduction into and beneath the surface of the stream which is different from the rate of stream movement and as such minimized the possibility of charge build-up on the surface of the stream at or adjacent to the drum 7. Should such surface build-up occur it may be advisable to rotate the drum at a circumferential rate of linear movement greater than the linear rate of movement of the stream itself.

In FIG. 3 is shown an alternative form of the invention wherein the stream 3 may serve as the vehicle for melting or otherwise processing a charge material consisting of somewhat larger pieces, such as for example scrap metal. Here, the physical force for submerging the charge takes the form of a resistence wall 107 having a sloped surface 107a which is slanted downwardly toward the surface of the stream in the direction of the current. The charging means 105 communicates with the elevated or upstream end of wall 107 so as to provide a stream entranceway 121 which enables the charge to be moved into the current of the stream and to come in contact with sloped surface 107a. The interacting forces of surface 107a and the current of stream 3 induce to the charge a downward force causing progressive and continued downward movement in the charge into and beneath the stream surface; simultaneously there is exerted on the metal particles which are pressed against the surface 107a, a constant wearing force by the stream current, thus causing the metal charge to be ground away in a manner similar to the grinding of an object by a grinding wheel. As this wetting process transpires, the viscosity of the charge approaches that of the stream until there is insufficient buoyancy to keep the charge thereabove and at which time it emerges from the downstream end 123 of wall 107.

In FIG. 4 there is shown in another illustration in which the concepts hereof may be adapted to the processing of a substantially continuous charge of small or particle-like substance. Here, stream entranceway 221 is defined by a relatively steeply sloped surface 207a which serves only to allow the charge to move away from the charging means 205. The acting wall 207 is substantially at or near the surface of the stream so as to enclose the charge and force it into and beneath the stream surface, substantially as a consequence of interacting wave action between the stream mass and the confining walls of trough 211.

In FIG. 5 there is shown yet another variance of the concept hereof. Here, there is provided a similar charging means 305 which is adapted to transmit a charge into the stream 3. The stream moves in a substantially uniform direction into and against the surface of reciprocating wall 307. The wall 307 is hinged at or near the downstream end 309 and moves substantially vertically in reciprocating fashion at the upstream end 310 so as to allow, at a selective rate, charge material to move into and through entranceway 321 and beneath the wall 307 along the length thereof. Acting surface 307a is adapted to come into contact with the floating charge and to force the same into and beneath the surface of the stream as it passes along the linear dimension of wall 307. Reciprocation of the wall is affected by hinged arm 313 and the rate of reciprocation thereof is influenced by such factors as the relative size of charged pieces, the linear rate of stream movement, the mass of stream movement per unit of time, and volume of charge introduced per unit of time, the relative wetting rate and buoyancy of the charge and other such factors.

In FIG. 6 there is shown yet another variation of the physical barrier or force means used to accelerate wetting and processing of the charged material. Here there is provided a plurality of stepped walls 407. By comparison to individual sloped walls such as is shown in FIG. 3 the plurality of offset sloped walls 407 provide for relief of charged material during the initial wetting and processing period. Such arrangement may facilitate the wetting and preclude built-up and possible freeze-up of charged material which have a low heat absorption rate. Such material will not readily wet and as a consequence would tend to obstruct continuous charging to the stream unless the physical wall 407 were designed to allow intermittent but continuous passage of such material. Furthermore, utilization of a series of sloped surfaces such as 407a induce to the charge movement a desired turbulence both within the stream and against sequential walls which enhances their physical breakdown into smaller pieces, this of course enhancing the rate of heat transfer thereto.

With reference to FIG. 7 there is shown a hot metal reservoir 701 enclosed by the walls of a furnace-like structure 702. An internal wall 703 of semicircular configuration is designed to assure movement of the molten metal through the reservoir without development of static areas of hot metal. The internal wall 7 03 is thus intended to facilitate continuous movement of the hot metal in stream-like manner. The furnace-like structure defined by walls 702 is further characterized by an inlet 705 and outlet 707 passage through which the molten metal communicates with a trough 709. The interior of the trough is adapted to carry the molten metal as a stream so that movement of the stream therethrough continuously recirculates the molten metal of the reservoir. Appropriately mounted above the stream is a plurality of lances 7 through which the charge material is fed. A charging container 710 may,

like FIG. 1, be disposed above the lance means 7 so that charged material may be continuously added to the stream 3 and forced beneath the surface thereof by the physical force of means 7 as the stream moves into inlet 705 and becomes a part of reservoir 701, and out again through outlet 707. Heat is appropriately added to the reservoir area by the conventional method and tapping of the product metal may occur at any desirable position within walls 702. The material may be charged to the system for purposes of melting or reducing or other processing, on a continuous basis. For example, particulate ores or concentrate, preferably preheated, and where necessary preblended with carbonaceous fuel, are fed pneumatically or by other means into the stream 3 through lances (or powder feeders) 7 which extend from charge containers 710. The stream 3 of molten material moves through trough 709 in a generally clockwise direction and is caused to flow by the aforementioned induction elevator disposed beneath the molten metal or by a refractory coated propeller or other mechanical means, not shown. Here the physical force by which the charge material is introduced to the stream constitutes the pressurized gas or oxygen which blows the particulate material through the lances 7 and into and beneath the stream surface. The lances 7 are shown in the drawing to terminate a short distance above the surface of the stream so that the particulate materials and/or gases injected therethrough are directed on the surface. It should be recognized, however, that any of the lances may be designed and arranged to project beneath the surface of the stream. Slag which is formed on the stream may be withdrawn through appropriate tap means (not shown).

It will be further clear that fluxing materials may be added to the stream along with the particulate ore or concentrates or other charge. Even very fine flux can appropriately be added through one or more of the lances.

With reference to FIG. 9 there is shown a reverbatory furnace, such as is used for smelting copper concentrates, the furnace being characterized by internal walls 902. Unlike conventional reverbatory furnaces, however, the furnace of FIG. 9 is characterized by an inlet end 905 and an outlet 907. A continuous stream of copper matte 3 is adapted to flow into the furnace through inlet 905 and out through outlet 907. The stream is designed to flow in closed loop manner by traversing the path of trough 909. Banks of copper concentrates 900 are disposed on each side of the matte stream 3 within the confines of the furnace walls 902, see FIG. 10, so that the stream 3 is adapted to flow between the banked concentrate thereby wearing the concentrate away from the bank and thus accelerating heat transfer from the stream to the concentrate mass. The increased rate of heat transfer from the stream to the mass which occurs as a consequence of moving the matte through the bank greatly accelerates the rate of chemical reaction and hence the rate of production. In addition, copper concentrate may be introduced from above onto the stream such as is shown in FIG. 1. These concentrates are generally of lighter density than the stream and in order to facilitate their dissolution in the stream a plurality of physical barrier means or drums 917 are selectively located so as to force the concentrate, or other feed material introduced, into and beneath the surface of the stream so as to thereby in- 10 crease the rate of heat transfer from the stream to the concentrate mass.

Operation of the system of FIGS. 9 and 10 may be optionally conducted by partially roasting the concentrates prior to introduction to the stream and by feeding the concentrates to the stream thereafter at a controlled rate. Partially roasted concentrates may thus achieve a magnetic characteristic. Positioning of a magnetic source beneath the stream surface will then draw the concentrates into and therebeneath the matte stream. The magnetic field source may take the form of a permanent magnet or it may be provided as an incident of use of an electromagnetic induction elevator, the primary function of which is to move the stream. As indicated earlier, however, motion may be imparted to the matte with means other than the induction elevator.

An example of concentrate used in the above system is present in the form of copper sulfide which is partially roasted prior to introduction to the matte stream. The copper sulfide is fed to the stream at a controlled rate and is drawn into the stream either by a magnetic force or is forced into the stream by the physical force means 917. At the point of immersion there is a reaction between sulfur and oxygen and some fulfur dioxide (S0 is released. The remaining sulfides are incorporated into the matte and slag is formed from the gangue and iron oxide in the feed. The matte then flows back to the furnace and, normally, the slag would go to the furnace as well. Not only is the rate of incorporation of concentration into the matte rapid, but also the circulation of matte through the furnace enhances the motion of the matte relative to the banks and to the slag. Most of the S0 that may be formed is liberated in an exit gas that is readily used for treatment purposes.

With reference now to FIGS. 11 and 12 there is shown another form of the invention. Here, a furnace enclosure is characterized by end walls 1111 and side walls 1112. An internal wall 1103 serves as a partition to define a furnace area having inlet 1105 and outlet 1107. A charging means 1105 may consist of an elongate refractory lined chimney through which a charge such as aluminum scrap may be introduced for melting purposes. I-Ieat source means 1114 are provided to maintain the charged scrap or other feed material in a molten state and a stream effect is produced by appropriate means 1116 such as driven rollers as disclosed earlier herein or by an induction pump or by the impellers schematically illustrated. The stream producing means 1116 are adapted to move the molten metal through the tunnel-like construction of charging means 1105 and produce a stream-like flow past outlet 1107 and back through the return channel to inlet 1105. In this way a continuous stream of molten metal is passed through the stack of charged material suchas scrap aluminum and there is produced an effective heat transfer between the molten metal and the solid scrap which is charged thereto. At the same time, off gases emanating from the piled scrap charge is conducted up through the charging means 1105 so as to drive off moisture and other volatiles and, in the case of aluminum, helps to reduce the tendency to form dross. The weight of the charged material itself forms the physical pressure by which the solid charge pieces are forced into and beneath the stream surface. In an alternative form of the invention, when the charge material constitutes particulate oxide to be reduced, the charge material may be introduced to the stream by utilizing the physical weight of the charge itself so long as such charge weight, or mass, functions to bring the charge material into the stream and below the surface thereof. Merely dropping the charge onto the streams surface is generally insufficient to accomplish the accelerated wetting and dissolution rate which are conducive to high volume processing. In other words, it is essential that the charge material be introduced not only onto the stream surface but into and beneath said surface in order that the material be fully immersed within the heated environment of the stream, thereby taking advantage of the maximum heat transfer rate between the stream and the charge. Here, FIG. 13, the charge material is fed through a charging chute or other charging means 1305 which extend beneath the stream surface so that when the charge exits the charging means it is submerged beneath the stream, see also FIGS. 11 and 12. The charge may, for example, consist of granular iron ore, or other metal oxides to be reduced and which because of their relatively light weight or density tend to float upon the surface of a stream of molten metal. Such charge material is introduced into the stream through the charging means and forced beneath the surface of the stream by utilizing the physical weight of the charge material itself which is stacked within the charging means or chute to a height which is influenced by certain characteristics of the stream of molten metal, such as the rate of movement of the stream and the physical dimensions of the stream which are in contact with the bottom of the stack of charge material. Thus the charge material is introduced to the molten metal stream 3 beneath the surface thereof through the charging chute or other means such as a pipe or the like. The granular-like oxide may be introduced to the stream either in cold or preheated condition through the aforementioned gravity feed or, if so desired, it may be forced into the stream by a screw feed (not shown), by other such mechanical means, or by use of an inert gas such as nitrogen, oxidizing gas such as air or a reducing gas such as natural gas. The reducing material employed in the process is a solid, liquid or gaseous reducing agent which is capable of exerting a carburizing action on the molten metal stream. This reducing agent may, therefore, comprise any number of materials such as powdered coke, oil, coal or natural gas and as previously indicated, may be introduced to the molten stream separately or as an admixture with the ore or oxide being reduced. A continuous or regularly intermittent supply of heat must be added to the system and this may be accomplished through the use of various fuels such as for example, oils or gases. The hot gaseous products produced by this combustion may be employed to preheat the oxygen containing gas.

With further reference to the illustration of FIG. 13, the improved process and method of the present invention may be utilized with metal oxides or ores in granular form other than iron. Chromium or manganese ores may be substituted in place of iron ores and treated in a similar manner to liberate the free metal components for subsequent intermixing with sponge iron to produce products of desired composition. Likewise, processes other than reduction may be the subject of the teachings disclosed herein. For example as explained with respect to FIGS. 9, and FIGS. 11 and 12, the charging methods can be used for the production of copper or the melting of metal scrap, or of course in other metal processes.

In regard to the embodiments disclosed herein, it will be recognized that the method taught for enhancing the 12 processing of charged material constitutes a moving molten metal bath which is adapted to move in a uniform direction, such as in a stream, and that such stream comprises the heat source and hence the processing vehicle for material charged thereto at a substantially continuous rate. Continuous movement of the charged material by the current of the stream in a first direction allows the utilization of a compressive or resistive physical force on the surface of the stream in order to effectively induce the charge into and beneath the stream surface where the most effective heat utilization can occur. The rolling, resistive and/or compressive forces herein disclosed are designed to accomplish this principal purpose in pursuit of accelerated processing of the charged material. Whether such processing takes the form of reduction, such as in the manufacture of molten iron from iron oxide, or whether it be the processing of an alloy metal such as the introduction of nickle or nickle compound to a molten metal stream, or whether it be smelting, refining, or merely melting constitutes no limitation upon the adaptation of the method herein. And it will be readily recognized that this method allows the practicing of any such processing step on a substantially continuous, and therefore most economical basis. It will likewise be recognized that utilization of a molten metal stream of endless design, i.e., closed loop allows for introduction of heat at any point in a manner thus ensuring heating of the entire metal mass. Likewise chemical agents may be introduced similarly. Still further, by-products from the stream, such as off-heat, may be fed to the material to be charged so as to pre-heat it while other by-products such as slag or gangue may be easily tapped.

The invention herein has been described with reference to a number of embodiments, which embodiments have been selected solely for exemplary purposes. It is therefore stated that the concepts hereof may be embodied in other structural designs so long as the advantages described may be accomplished without the introduction of adversity. The scope of the invention should thus be determined in accordance with the spirit hereof and within the terms of the claims appended hereto.

Therefore, that which is desired to be secured by United States Letters Patent is:

1. In a method for enhancing the processing of metal, including ores, compounds and concentrates thereof, on a substantially continuous basis in a molten metal stream by optimising heat transfer of the stream to the metal to be charged thereto comprising the steps of:

providing a coherent stream of molten metal that constitutes the medium in which processing takes place, said stream being characterized by a discreet width and length, the length including a longitudinal axis in the direction of stream flow,

introducing to the stream on a substantially continuous basis a material charge, said material charge occuring at an area of introduction above the linearly moving stream,

constantly moving said stream past the area of introduction there beneath and thus moving the charged material also away from the area of introduction and thus presenting an entirely new mass of stream beneath the area of introduction so as to thus maintain a constant temperature of molten metal in the stream at the area of introduction, thereby maximizing the rate of heat transferred to the charged material,

disposing a physical barrier means downstream of the point of introduction to the stream of the material charge and such that said barrier means is in contacting relation to the charged material floating in the stream and which is exposed above the surface thereof, said physical barrier means applying physical force to the charged material on the stream surface so as to physically submerge the charged material below the streams surface, said physical barrier means being substantially coterminous with the stream width to thereby insure complete physical submersion of all of the material charge.

2. The method of claim 1 wherein said barrier means comprises a roll whose circumferential surface substantially contacts the molten stream; the width of the roll being substantially the same as the width of the stream so that all of the charge is forced into the stream before passing the roll and moving downstream thereof.

3. The method of claim 1 wherein said charge of said metal is substantially the same as the molten metal of the stream, so that the introduction thereof increases the metal of the stream.

4. The method of claim 1 wherein said charge of said metal is substantially the same as the metal of the stream tapping the molten product metal from the stream,

and also tapping by-products, as desired. 5. The method of claim 1 including the additional step of recirculating the stream by designing its path to traverse a closed loop so as to form an endless stream of moving molten metal,

introducing said charge of metal on a substantially continuous basis, said charged metal being continually moved away by the stream current from the area of introduction and toward said physical barrier means where immersion of the charge takes place, thus facilitating the processing thereof, and,

adding heat to the stream as required, in order to maintain the operating temperature necessary for processing in the stream.

6. The method of claim 5 wherein chemical agents are added to the stream for accomplishing desired chemical reactions with the molten metal,

tapping product metal and by-products from the stream as may be desired.

7. The method of claim 1 wherein said physical barrier means comprises a resistance wall having a sloped surface above the stream, the elevated end of the sloped surface being adjacent the charging area so that metal introduced to stream thereat is carried by the current into contact with the resistance wall, which, while tending to force the metal into and beneath the stream surface contemporaneously holds the metal while the stream current imparts its dynamic force and heat toward the dissolution thereof.

8. The method of claim 5 wherein said physical barrier means comprises a resistance wall having a sloped surface above the stream, the elevated end of the sloped surface being adjacent the charging area so that metal introduced to stream thereat is carried by the current into contact with the resistance wall, which, while tending to force the metal into and beneath the stream surface contemporaneously holds the metal 14 while the stream current imparts its dynamic force and heat toward the dissolution thereof.

9. The method of claim 6 wherein said physical barrier means comprises a resistance wall having a sloped surface above the stream, the elevated end of the sloped surface being adjacent the charging area so that metal introduced to stream thereat is carried by the current into contact with the resistance wall, which, while tending to force the metal into and beneath the stream surface contemporaneously holds the metal while the stream current imparts its dynamic force and heat toward the dissolution thereof.

10. The method of claim 5 wherein said barrier means comprises a roll whose circumferential surface substantially contacts the molten stream; the width of the roll being substantially the same as the width of the stream so that all of the charge is forced into the stream before passing the roll and moving downstream thereof.

11. The method of claim 1 wherein said physical barrier means consists of a wall disposed above the surface of the stream, said wall reciprocally moving upward and downward to the stream so as to force the metal charge exposed thereon into and beneath the surface.

12. The method of claim 5 wherein said physical barrier means consists of a wall disposed above the surface of the stream, said wall reciprocally moving upward and downward to the stream so as to force the metal charge exposed thereon into and beneath the surface.

13. The method of claim 12 wherein chemical agents are added to the stream for accomplishing desired chemical reactions with the molten metal,

tapping product metal and by-products from the stream as may be desired.

14. The method of claim 1 wherein said physical barrier means comprises a plurality of stepped walls, each disposed with their lower ends in operative relation to the stream flowing thereby, the upper ends thereof serving to relieve pressure on charged material and thus reduce build up of charge beneath the wall surface.

15. The method of claim 5 wherein said physical barrier means comprises a plurality of stepped walls, each disposed with their lower ends in operative relation to the stream flowing thereby, the upper ends thereof serving to relieve pressure on charged material and thus reduce build up of charge beneath the wall surface.

16. The method of claim 1 including the additional step of introducing to the stream a chemical processing agent in order to accomplish a predetermined chemical reaction with the molten metal mass.

17. The method of claim 16 including the additional step of tapping product metal and by-products, as required.

18. The method of claim 16 including the additional step of passing a gaseous agent over the surface of the stream so as to effectuate a chemical reaction with the molten mass thereof.

19. The method of claim 18, including the additional step of tapping product metal and by-products, as required. 

1. IN A METHOD FOR ENHANCING THE PROCESSING OF METAL, INCLUDING ORES, COMPOUNDS AND CONCENTRATES THEREOF, ON A SUBSTANTIALLY CONTINUOUS BASIS IN A MOLTEN METAL STREAM BY OPTIMISING HEAT TRANSFER OF THE STREAM TO THE METAL TO BE CHARGED THERETO COMPRISING THE STEPS OF: PROVIDING A COHERENT STREAM OF MOLTEN METAL THAT CONSTITUTES THE MEDIUM IN WHICH PROCESSING TAKES PLACE, SAID STREAM BEING CHARACTERIZED BY A DISCREET WIDTH AND LENGTH, THE LENGTH INCLUDING A CONGITUDINAL AXIS IN THE DIRECTION OF STREAM FLOW, INTRODUCING TO THE STREAM ON A SUBSTANTIALLY CONTINUOUS BASIS A MATERIAL CHARGE, SAID MATERIAL CHARGE OCCURING AT AN AREA OF INTRODUCTION ABOVE THE LINEARLY MOVING STREAM, CONSTANTLY MOVING SAID STREAM PAST THE AREA OF INTRODUCTION THERE BENEATH AND THUS MOVING THE CHARGED MATERIAL ALSO AWAY FROM THE AREA OF INTRODUCTION AND THUS PRESENTING AN ENTIRELY NEW MASS OF STREAM BENEATH THE AREA OF INTRODUCTION SO AS TO THUS MAINTAIN A CONSTANT TEMPERATURE OF MOLTEN METAL IN THE STREAM AT THE AREA OF INTRODUCTION, THEREBY MAXIMIZING THE RATE OF HEAT TRANSFERRED TO THE CHARGED MATERIAL, DISPOSING A PHYSICAL BARRIER MEANS DOWNSTREAM OF THE POINT OF INTRODUCTION TO THE STREAM OF THE MATERIAL CHARGE AND SUCH THAT SAID BARRIER MEANS IS IN CONTACTING RELATION TO THE CHARGED MATERIAL FLOATING IN THE STREAM AND WHICH IS EXPOSED ABOVE THE SURFACE THEREOF, SAID PHYSICAL BARRIER MEANS APPLYING PHYSICAL FORCE TO THE CHARGED MATERIAL ON THE STREAM SURFACE SO AS TO PHYSICALLY SUBMERGE THE CHARGED MATERIAL BELOW THE STREAMS SURFACE, SAID PHYSICAL BARRIER MEANS BEING SUBSTANTIALLY COTERMINOUS WITH THE STREAM WIDTH TO THEREBY INSURE COMPLETE PHYSICAL SUBMERSION OF ALL OF THE MATERIAL CHARGE.
 2. The method of claim 1 wherein said barrier means comprises a roll whose circumferential surface substantially contacts the molten stream; the width of the roll being substantially the same as the width of the stream so that all of the charge is forced into the stream before passing the roll and moving downstream thereof.
 3. The method of claim 1 wherein said charge of said metal is substantially the same as the molten metal of the stream, so that the introduction thereof increases the metal of the stream.
 4. The method of claim 1 wherein said charge of said metal is substantially the same as the metal of the stream tapping the molten product metal from the stream, and also tapping by-products, as desired.
 5. The method of claim 1 including the additional step of recirculating the stream by designing its path to traverse a closed loop so as to form an endless stream of moving molten metal, introducing said charge of metal on a substantially continuous basis, said charged metal being continually moved away by the stream current from the area of introduction and toward said physical barrier means where immersion of the charge takes place, thus facilitating the processing thereof, and, adding heat to the stream as required, in order to maintain the operating temperature necessary for processing in the stream.
 6. The method of claim 5 wherein chemical agents are added to the stream for accomplishing desired chemical reactions with the molten metal, tapping product metal and by-products from the stream as may be desired.
 7. The method of claim 1 wherein said physical barrier means comprises a resistance wall having a sloped surface above the stream, the elevated end of the sloped surface being adjacent the charging area so that metal introduced to stream thereat is carried by the current into contact with the resistance wall, which, while tending to force the metal into and beneath the stream surface contemporaneously holds the metal while the stream current imparts its dynamic force and heat toward the dissolution thereof.
 8. The method of claim 5 wherein said physical barrier means comprises a resistance wall having a sloped surface above the stream, the elevated end of the sloped surface being adjacent the charging area so that metal introduced to stream thereat is carried by the current into contact with the resistance wall, which, while tending to force the metal into and beneath the stream surface contemporaneously holds the metal while the stream current imparts its dynamic force and heat toward the dissolution thereof.
 9. The method of claim 6 wherein said physical barrier means comprises a resistance wall having a sloped surface above the stream, the elevated end of the sloped surface being adjacent the charging area so that metal introduced to stream thereat is carried by the current into contact with the resistance wall, which, while tending to force the metal into and beneath the stream surface contemporaneously holds the metal while the stream current imparts its dynamic force and heat toward the dissolution thereof.
 10. The method of claim 5 wherein said barrier means comprises a roll whose circumferential surface substantially contacts the molten stream; the width of the roll being substantially the same as the width of the stream so that all of the charge is forced into the stream before passing the roll and moving downstream thereof.
 11. The method of claim 1 wherein said physical barrier means consists of a wall disposed above the surface of the stream, said wall reciprocally moving upward and downward to the stream so as to force the metal charge exposed thereon into and beneath the surface.
 12. The method of claim 5 wherein said physical barrieR means consists of a wall disposed above the surface of the stream, said wall reciprocally moving upward and downward to the stream so as to force the metal charge exposed thereon into and beneath the surface.
 13. The method of claim 12 wherein chemical agents are added to the stream for accomplishing desired chemical reactions with the molten metal, tapping product metal and by-products from the stream as may be desired.
 14. The method of claim 1 wherein said physical barrier means comprises a plurality of stepped walls, each disposed with their lower ends in operative relation to the stream flowing thereby, the upper ends thereof serving to relieve pressure on charged material and thus reduce build up of charge beneath the wall surface.
 15. The method of claim 5 wherein said physical barrier means comprises a plurality of stepped walls, each disposed with their lower ends in operative relation to the stream flowing thereby, the upper ends thereof serving to relieve pressure on charged material and thus reduce build up of charge beneath the wall surface.
 16. The method of claim 1 including the additional step of introducing to the stream a chemical processing agent in order to accomplish a predetermined chemical reaction with the molten metal mass.
 17. The method of claim 16 including the additional step of tapping product metal and by-products, as required.
 18. The method of claim 16 including the additional step of passing a gaseous agent over the surface of the stream so as to effectuate a chemical reaction with the molten mass thereof.
 19. The method of claim 18, including the additional step of tapping product metal and by-products, as required. 